A hellhound is a dog of Hell, found in mythology, folklore and fiction.

Hellhounds typically have features such as an unnaturally large size, a black fur color, glowing red eyes, super strength or speed, ghostly or phantom characteristics, and sometimes even the ability to talk.

Hellhounds are often associated with fire, and may have fire-based abilities and appearances.

They are often assigned to guard the entrance to the world of the dead or undertake other duties related to the afterlife or the supernatural, such as hunting down lost souls or guarding a supernatural treasure.

As legend goes, if one happened to see the hellhound three times, he or she will die an abrupt and unseen death.

Perhaps best known in popular culture as a demonic dog, it is also an antiquated way of inoffensively directing slight frustration towards somebody. Still occasionally used in Latin American vernacular.

"What do you mean there's none left?"
"Sorry man, I've eaten all the pancakes"
"You, my friend, are a hellhound!"